MPM simulation of frictional heating-induced hypermobility of landslides

Frictional heating-induced thermal pressurization is a key mechanism responsible for the exceptional long-runout distances and high-speed movement of some massive landslides. In this paper, a novel framework for modelling landslides with frictional heating-induced thermal pressurization is developed based on the material point method (MPM). In this MPM framework, the basal terrain is idealised as a rigid material, while the sliding mass is treated as a thermo-hydro-mechanical porous mixture. The sliding mass interacts with the rigid terrain via the generalized multi-material contact model accounting for frictional heating and water pressurization effect. Special scaling treatment is applied for the temperature and liquid pressure diffusion calculations within the sliding mass to better approximating the thermal pressurization effect within the thin shear band. The validity of the thermal pressurization model and the sensitivity of its parameters have been demonstrated through two benchmark examples, corresponding to thermo-poro-elastic blocks sliding on a horizontal surface with an imposed constant velocity and along an inclined plane under gravity. Finally, the capability of the proposed framework is verified by satisfyingly reproducing both the dynamic runout and the friction-induced thermal pressurization processes of the giant Daguangbao landslide.